1. Field of the Invention
The present invention relates generally to the field of respiratory devices and methods. More specifically, the present invention discloses a method and apparatus for guiding insertion of an endotracheal tube while the patient continues to receive ventilation or cardiopulmonary resuscitation.
2. Statement of the Problem
In emergency situations involving cardiopulmonary patients or other patients with compromised or arrested breathing, an oral airway is first inserted into the patient""s mouth. A face mask is then placed over the patient""s mouth and nose. The face mask is connected to an inflatable bag to maintain at least minimal oxygen flow to the lungs in the short term. This process is sometimes referred to as xe2x80x9cbaggingxe2x80x9d the patient. It is suitable for initially stabilizing the patient. In order to breathe more effectively for the patient during cardiopulmonary resuscitation, and to prevent aspiration of stomach contents, an endotracheal tube (or ET tube) is placed into the trachea. Longer-term care usually requires attaching the patient to a ventilator (e.g., by means of the endotracheal tube). The transition from face mask to breathing through the endotracheal tube can be dangerous if insertion of the endotracheal tube takes too long, because the mask and oral airway must be removed and the flow of air/oxygen is interrupted while the endotracheal tube is inserted through the patient""s mouth.
The typical conventional approach to making this transition involves discontinuing resuscitation and completely removing the mask and oral airway to expose the mouth. The physician inserts a rigid laryngoscope blade into the patient""s mouth to ensure that the patient""s airway is open, and then attempts to insert the endotracheal tube through the patient""s mouth and into the trachea in the conventional manner. This may require a significant amount of time, particularly if the patient is less than completely cooperative and relaxed, or if the patient""s airway has suffered trauma, or the tongue has fallen back to close the airway. The patient may not be breathing during this time, or may not be breathing sufficiently to maintain adequate blood oxygen levels. If the transition process takes more than a few seconds, the physician must temporarily abandon the effort and return to resuscitation by reinserting the oral airway and replacing the face mask. The transition process may have to be repeated several times before the endotracheal tube is successfully installed. In addition, the speed with which the transition process must be completed increases the chances of a mistake being made or unnecessary injury to the patient during the intubation procedure.
Endotracheal tubes are also used in semi-emergency situations to ventilate patients with respiratory failure who may be conscious or semi-conscious. The conventional approach requires the patient to lie still while the physician inserts a rigid laryngoscope blade into the patient""s mouth and trachea. Delivery of ventilation and/or oxygen is also interrupted during this period. The endotracheal tube is then inserted into place while the laryngoscope blade keeps the patient""s airway open. Successful intubation depends on the patient being cooperative and completely relaxed, which unfortunately is often not the case. Even with a cooperative patient, intubation is very uncomfortable and can cause the patient to panic due to the difficulty in breathing during the procedure. This procedure can also result in a choking or gagging response that can cause the patient to regurgitate and aspirate contents from the stomach. One conventional response to these shortcomings has been to sedate the patient during intubation. Tranquilizers make the patient more cooperative and less likely to choke during intubation, but also tend to suppress the patient""s breathing and blood pressure. These side effects may be unacceptable when dealing with a patient who already suffers from shallow or irregular breathing or depressed blood pressure. Therefore, a need exists for an improved device to guide insertion of an endotracheal tube and ensure that the patient""s airway is open, and that also allows the patient to continue to receive air/oxygen during the insertion process.
A wide variety of devices that combine face masks with tubes for ventilation (e.g., endotracheal tubes) have been used in the past, including the following:
Teves discloses a system for dispensing oxygen or anesthesia via an interchangeable face mask and nasal catheter.
Don Michael discloses a endotracheal-esophageal intubation device that includes a face mask (see, FIG. 2 of the Don Michael patent).
Jeshuran shows an anesthesia mask 28 that is initially placed over the patient""s mouth and nose as shown in FIG. 7 of the Jeshuran patent. A fiber optic 40 is inserted through an endotracheal tube, and then through an opening in a two-piece core 84, 86, as shown in FIG. 9 of the Jeshuran patent. The fiber optic 40 is advanced into the trachea. The head 96 is then unscrewed and the core segments 84, 86 are disassembled to allow the endotracheal tube to be inserted through the mask, as shown in FIG. 2 of the Jeshuran patent. The fiber optic 40 serves as a guide for insertion of the endotracheal tube 46. The fiber optic 40 is then withdrawn and the endotracheal tube cuff 136 is inflated, as shown in FIG. 8 of the Jeshuran patent. However, Jeshuran does not show a curved guide to direct insertion of the fiber optic probe. The physician is faced with the problem of navigating the fiber optic probe past the patient""s tongue and along the airway.
Northway-Meyer discloses a device for pulmonary ventilation concurrent with fiber optic examination of the respiratory tract and tracheal intubation. In particular, Northway-Meyer discloses a face mask with a plurality of ports for ventilation and intubation of the patient, and curved guide for advancing an endotracheal tube.
Kondur discloses another example of an adapter 10 that allows insertion of an endotracheal tube 40 through the face mask 50 and nose of the patient. Here again, no curved guide is provided.
Donmichael discloses an esophageal obturator for blocking aspiration of stomach fluids while the face mask is being used for ventilating the lungs.
Dryden discloses a two-tube resuscitation system. One tube is used to supply air to the trachea, while the other tube is used for aspiration or administering medication.
Buttaravoli discloses a resuscitator having a face mask 11 with a curved tube 15 for supplying air to the patient""s airway.
Michael et al. disclose an apparatus for sealing a patient""s esophagus and providing artificial respiration. The apparatus includes a mouth shield 14 and a curved main tube 10.
In addition, the prior art includes several references involving intubating pharyngeal airways that have a curved tubular member, including the following:
The Parker ""805 patent discloses a curved guide for intubation of a patient""s trachea or suctioning of the hypopharynx or esophagus.
The Parker ""254 patent discloses a curved guide for orotracheal intubation.
Augustine discloses a tracheal intubation guide with a curved forward end.
The Berman patents show an intubating pharyngeal airway having a side access for passage of a tube. The side opening can be expanded or closed by means of either a hinge on the opposite side wall of the tube or by a cap.
Finally, the prior art includes several examples in which supplemental air/oxygen is supplied through a secondary lumen extending along a laryngoscope or ventilating airway, including the following:
Ha discloses an anesthetic laryngoscope with a handle and a blade having an observation light and a oxygen supply tube mounted thereon.
Hete et al. disclose an insufflation system that includes a first tube that inserts into a patient""s airway to provide a primary flow of gas from a ventilator. A second, insufflation catheter is provided within the first tube for delivering a flow of insufflation gas to the patient.
Kurtis discloses a neonatal resuscitation device that includes an endotracheal tube with lumens that can be used either for suction or ventilation.
Bartlett discloses a laryngoscope with a handle and a blade having a suction tube and a plurality of other channels extending along its length.
Watson et al. disclose an emergency ventilation tube having coaxial tubular members for ventilating the patient and inflating a cuff at the distal end of the ventilation tube. The device can also be used in conjunction with a face mask.
May discloses a laryngoscope blade having conduits for suction and ventilation, and a light source for illumination.
3. Solution to the Problem
None of the prior art references discussed above show an intubation guide that allows continued ventilation of the patient via a second lumen while the endotracheal tube is being inserted into the patient""s airway. The guide may also be used in conjunction with a face mask for initial resuscitation of the patient. During intubation, a fiber optic probe is inserted through the endotracheal tube and this assembly is advanced along the guide. The curved distal portion of the guide directs the fiber optic probe and endotracheal tube along the patient""s airway while ventilation continues. After the distal end of the fiber optic probe has guided the endotracheal tube past the larynx and into the trachea, the guide and mask are withdrawn over the fiber optic probe. The fiber optic probe can used to monitor the position of the distal end of the endotracheal tube during this step to ensure that it remains in the proper position. The fiber optic probe can then be withdrawn and the endotracheal tube is be connected to an external ventilator. Alternatively, the guide can be left in place to serve as a bite guard.
This system allows the endotracheal tube to be inserted and connected to a ventilator without interrupting the flow of air/oxygen to the patient""s lungs. In addition, the curved guide greatly simplifies insertion of the fiber optic probe and endotracheal tube by providing direction and maintaining an open passageway past the patient""s tongue and into the hypopharynx.
The supplemental flow of air/oxygen through the second lumen helps to maintain the patient""s blood oxygen level and flushes carbon dioxide from the patient""s lungs during intubation. Optionally, a third lumen extending along the guide can be used to monitor the carbon dioxide level within the patient""s airway.
This invention provides a method and apparatus for guiding insertion of an endotracheal tube into a patient""s trachea while continuing to supply air/oxygen into the patient""s airway and lungs. A guide having a curved distal portion is inserted into the patient""s mouth and hypopharynx. A second lumen extending along the guide is used to supply air or oxygen into the patient""s airway and to flush carbon dioxide from the lungs. A fiber optic probe is inserted through an endotracheal tube and this assembly is advanced along the guide into the patient""s airway, while ventilation continues without interruption through the second lumen. The direction of the distal tip of the fiber optic probe can be controlled by the physician. This allows the physician to carefully guide the fiber optic probe and endotracheal tube to a position past the larynx while ventilation continues. After the distal end of the fiber optic probe has guided the endotracheal tube past the larynx and into the trachea, the guide and mask are withdrawn over the fiber optic probe. The fiber optic probe can used to monitor the position of the distal end of the endotracheal tube during this step to ensure that it remains in position. The fiber optic probe is then removed from within the endotracheal tube. The cuff on the endotracheal tube is inflated and a ventilator is connected to the proximal end of the endotracheal tube to ventilate the patient.
A primary object of the present invention is to provide a method and apparatus for guiding insertion of an endotracheal tube that does not require interruption of the ventilation process.
Another object of the present invention is to provide a method and apparatus for improving insertion of an endotracheal tube by helping to keep the patient""s airway open, and also allowing the physician to guide the insertion process via the fiber optic probe.
Another object of the present invention is to provide a method and apparatus for guiding insertion of an endotracheal tube that lessens the risk of injury and reduces patient discomfort.
Another object of the present invention is to achieve oxygenation and ventilation of the patient while the hands of the healthcare provider remain free to perform intubation.
Another object of the present invention is to allow for monitoring of gases (e.g., carbon dioxide) in the patient""s airway.
Yet another object of the present invention is to provide a method and apparatus for instilling local anesthetic into the patient""s airway prior to, or during insertion of the endotracheal tube.
These and other advantages, features, and objects of the present invention will be more readily understood in view of the following detailed description and the drawings.